1. Field of the Invention
This invention relates to powdery green tea prepared by pulverizing crude green tea; more specifically, the invention relates to a method for producing green tea in a microfine powder, comprising a modified pulverizing process and modified processes thereafter, and green tea in a microfine powder as prepared by the method.
2. Description of the Related art
Green tea contains enormous amounts of nutrients, such as vitamins E, C and A, catechin and theanine. It has been said in recent years that active oxygen is one of the factors affecting disadvantageously human health and promoting aging. Meanwhile, green tea contains a higher content of superoxide dismutase (SOD) as an enzyme eliminating active oxygen. SOD was discovered in 1969 by J. M. McCord and I. Fridovich. In Modern Medicine, Vol. 28, No. 8, 1996, SOD is presented to function as a preventive system against oxidative damage.
Hence, not only green tea drinking in general fashion but also the intake of green tea per se has been recommended; for example, powdery green tea prepared by pulverizing dried crude green tea with a grinder or the like has been developed. Herein, crude green tea is prepared by steaming fresh green tea leaves and subjecting the resulting green tea leaves to processes for coarse rubbing, rubbing and twisting, moderate rubbing and fine rubbing.
The particles of general powdery green tea and pulverized green tea are at about 3 to 10 microns. Therefore, nutrients therein cannot effectively be absorbed even if these types of green tea are ingested directly as they are. Additionally, the SOD potency of eliminating active oxygen is sometimes lost in the process of green tea preparation.
This invention has been proposed to overcome the problems of the conventional art. It is an object of the invention to provide green tea in a microfine powder at a high ratio of nutrient digestion and absorption and with high active oxygen-eliminating potency of SOD contained in the green tea.
So as to attain the above object, the method for preparing green tea in a microfine powder in accordance with the invention comprises pulverizing crude green tea into a microfine powder, spraying water to the resulting microfine powder and agitating the powder, and heating the microfine powder with infrared rays.
According to the method for preparing green tea in a microfine powder as described above, heating with an infrared ray after the preparation of the microfine powder can increase the ratio of nutrient digestion and absorption and can enhance the SOD potency to eliminate active oxygen.
Preferably, the inventive method for preparing green tea in a microfine powder comprises pulverizing crude green tea into a microfine powder of 1 micron or less, spraying water to the resulting microfine powder to a final moisture content of 6 to 8% and agitating the powder, and heating the microfine powder with infrared ray at a temperature of 40xc2x0 C. to 65xc2x0 C. for 130 minutes to 180 minutes.
The inventive green tea in such microfine powder is prepared by pulverizing crude green tea into a microfine powder of 1 micron or less and the green tea exerts active oxygen-eliminating potency of 0.7xc3x97105 to 1.8xc3x97105 per 1g of the green tea due to superoxide dismutase contained therein.
According to the method for preparing green tea in a microfine powder and owing to the resulting green tea in such microfine powder, the ratio of nutrient digestion and absorption can be improved profoundly by preparing the green tea in a microfine powder at 1 micron or less, while the steaming process under the above conditions can enhance the SOD potency to eliminate active oxygen by several tens-fold that of general green tea of middle grade.